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-rw-r--r--drivers/thunderbolt/lc.c179
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
new file mode 100644
index 000000000000..ae1e92611c3e
--- /dev/null
+++ b/drivers/thunderbolt/lc.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt link controller support
+ *
+ * Copyright (C) 2019, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include "tb.h"
+
+/**
+ * tb_lc_read_uuid() - Read switch UUID from link controller common register
+ * @sw: Switch whose UUID is read
+ * @uuid: UUID is placed here
+ */
+int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid)
+{
+ if (!sw->cap_lc)
+ return -EINVAL;
+ return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4);
+}
+
+static int read_lc_desc(struct tb_switch *sw, u32 *desc)
+{
+ if (!sw->cap_lc)
+ return -EINVAL;
+ return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1);
+}
+
+static int find_port_lc_cap(struct tb_port *port)
+{
+ struct tb_switch *sw = port->sw;
+ int start, phys, ret, size;
+ u32 desc;
+
+ ret = read_lc_desc(sw, &desc);
+ if (ret)
+ return ret;
+
+ /* Start of port LC registers */
+ start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
+ size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
+ phys = tb_phy_port_from_link(port->port);
+
+ return sw->cap_lc + start + phys * size;
+}
+
+static int tb_lc_configure_lane(struct tb_port *port, bool configure)
+{
+ bool upstream = tb_is_upstream_port(port);
+ struct tb_switch *sw = port->sw;
+ u32 ctrl, lane;
+ int cap, ret;
+
+ if (sw->generation < 2)
+ return 0;
+
+ cap = find_port_lc_cap(port);
+ if (cap < 0)
+ return cap;
+
+ ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+ if (ret)
+ return ret;
+
+ /* Resolve correct lane */
+ if (port->port % 2)
+ lane = TB_LC_SX_CTRL_L1C;
+ else
+ lane = TB_LC_SX_CTRL_L2C;
+
+ if (configure) {
+ ctrl |= lane;
+ if (upstream)
+ ctrl |= TB_LC_SX_CTRL_UPSTREAM;
+ } else {
+ ctrl &= ~lane;
+ if (upstream)
+ ctrl &= ~TB_LC_SX_CTRL_UPSTREAM;
+ }
+
+ return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+}
+
+/**
+ * tb_lc_configure_link() - Let LC know about configured link
+ * @sw: Switch that is being added
+ *
+ * Informs LC of both parent switch and @sw that there is established
+ * link between the two.
+ */
+int tb_lc_configure_link(struct tb_switch *sw)
+{
+ struct tb_port *up, *down;
+ int ret;
+
+ if (!sw->config.enabled || !tb_route(sw))
+ return 0;
+
+ up = tb_upstream_port(sw);
+ down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+ /* Configure parent link toward this switch */
+ ret = tb_lc_configure_lane(down, true);
+ if (ret)
+ return ret;
+
+ /* Configure upstream link from this switch to the parent */
+ ret = tb_lc_configure_lane(up, true);
+ if (ret)
+ tb_lc_configure_lane(down, false);
+
+ return ret;
+}
+
+/**
+ * tb_lc_unconfigure_link() - Let LC know about unconfigured link
+ * @sw: Switch to unconfigure
+ *
+ * Informs LC of both parent switch and @sw that the link between the
+ * two does not exist anymore.
+ */
+void tb_lc_unconfigure_link(struct tb_switch *sw)
+{
+ struct tb_port *up, *down;
+
+ if (sw->is_unplugged || !sw->config.enabled || !tb_route(sw))
+ return;
+
+ up = tb_upstream_port(sw);
+ down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+ tb_lc_configure_lane(up, false);
+ tb_lc_configure_lane(down, false);
+}
+
+/**
+ * tb_lc_set_sleep() - Inform LC that the switch is going to sleep
+ * @sw: Switch to set sleep
+ *
+ * Let the switch link controllers know that the switch is going to
+ * sleep.
+ */
+int tb_lc_set_sleep(struct tb_switch *sw)
+{
+ int start, size, nlc, ret, i;
+ u32 desc;
+
+ if (sw->generation < 2)
+ return 0;
+
+ ret = read_lc_desc(sw, &desc);
+ if (ret)
+ return ret;
+
+ /* Figure out number of link controllers */
+ nlc = desc & TB_LC_DESC_NLC_MASK;
+ start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
+ size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
+
+ /* For each link controller set sleep bit */
+ for (i = 0; i < nlc; i++) {
+ unsigned int offset = sw->cap_lc + start + i * size;
+ u32 ctrl;
+
+ ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
+ offset + TB_LC_SX_CTRL, 1);
+ if (ret)
+ return ret;
+
+ ctrl |= TB_LC_SX_CTRL_SLP;
+ ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
+ offset + TB_LC_SX_CTRL, 1);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}